Stable casein solution



Patented Apr. i1, lose 8.15M STABLE OABEIN SOLUTION ,Oarl Iddings, Staten Island, N. Y uslgnor to The Murals ew York No Drawing.

Company, Ina, a corporation of Appli tion December l, 1918, Serial No. 101.578

:1 claim. (or. lei-1s) This invention relates to stable casein solutions andtheir production. to be used for the manufacture of water paste paints, water-oil emulsions, glues, sizes and the like. These solutions are also intended for the preparation of coating compositions adapted to be applied to walls, floora'leather. paper, etc.. and they may further serve as a basis for printing inks.

One obiect of the present invention is the production of a casein solution which maintains substantially its initial viscosity or which does not substantially diminish in viscosity and which also displayes a tendency to putrefy is thus charfintlerised by high stability over long periods of Another object of the present invention is the production of a casein solution or suspension which remains stable regardless of whether it is subsequently rendered slightly acidic or slightly alkaline.

A third object of the present inventlonis the manufacture of a casein solution or suspension which possesses a heavy body and yet will retain its flowing properties.

It is well established from the prior art that slightly basic stable casein solutions have never been achieved by dissolving ordinary casein in alkalis. I am well aware however thatcasein solutions have been produced in the past by peptizing casein with fluorides as exemplified by United States Patent No. 1,506,608 to Regnier and United States Patent No. 1,893,608 to Atwood. Ail of these prior disclosures however, fail to disclose methods of preparing casein solutions which will remain stable for long periods of time, or which may be rendered alkaline and retain their stability. Solutions heretofore produced are further objectionable because of their rather thin body in proportion to casein content as compared with my solutions.

According to my invention, casein is peptized and/or dissolved at elevated temperatures in the presence of small amounts of sodium fluoride or other compounds of alkaline nature or compounds that possess a distinct peptizing or dispersing action on the casein, and a predetermined amount of water. If too much water is used, the casein has a tendency to swell to a curdy gelatinous'mass but it fails to dissolve into a smooth, creamy and translucent composition which is 'required for the aforementioned purposes. on the other hand, if too small an amdunt of water isemployed, the casein becomes too stiff for proper stirring, and consequently the mass adheres to the walls of the container during the initial heatperiod. Larger amounts of water, 450 parts or more may be used,"and have been ingstages whichcausesunevenheating andobiectionable darkening in color of the casein. when casein is dissolved in accordance with my invention, it does not appear to swell through a I have found by experimentation that sodium fluoride has the property of peptizing casein. partially neutralizing the same, and of renderingthe resulting solution resistant to hydrolysis and attack by micro-organisms. I have found many other substances which possess the property of peptising casein, and find that they are quite satisfactory for the preparation of various solutions, it being necessary in such cases only to add a suitable preservative, such as chlorphenol, to render the solution resistant to attack by micro-organisms. I prefer to use sodium fluoride for my purposes because it combines both of these desirable functions.

I prefer to use sodium fluoride in amounts varying from 14 to 20 parts per parts of commercial, acid-precipitated casein, although satisfactory results may be obtained by slightly varying these proportions, and I have found that no additional compounds are required to produce satisfactory casein solutions. According to my experiments, a temperature of I. is too low to produce a smooth appearing solution which will retain its stability for long periods of time, and for this reason I prefer in accordance with my discovery to use higher temperatures, namely between 1'10 and 210' I". Temperatures between and 1''. have been found to be the optimum for producing my stable casein solutions and in some casesv a minimum of 180' 1". is necessary. As far as the addition of water is concerned, I have discovered that it is undesirable to use less than 125 parts of water per 100 parts of casein during the initial heating for example,

found to yield smooth, stable solutions. Bolutions prepared with this quantity of water, however, have slightly thinner body and slightly lowvalues than those prepared with lesser In order to achieve a more ii i gi value as low as 4.8. Casein precipitated with hydrochloric acid, due to the volatility of this acid, is relatively free from excessive acid and dissolves very easily when treated according to my process. However, my invention is not limited to such hydrochloric acid-precipitated casein since the excessive acid of other caseins may be compensated by using a larger amount of sodium fluoride. l'br purposes of economy however. I prefer to add to such caseins, very small quantities of an alkaline borax, sodium silicates, dium carbonate, ammonium carbonate, ammonium hydroxide. etc., that is to say, such alkaline compounds which do not produce insoluble caseinates, to take care of their excessive acids. and the amount of such alkali used is slightly in excase of that amount required for neutralization of the excessive acids but insumcient to effect the solution of the casein by itself. By regulating the excessive acid of casein products prior to the ,fluoride treatment, satisfactory solutions may be obtained from any type of commercial, acid-precipltated caseins.

My process, however, in its broader aspects, is not limited to the use of fluorides, such as sodium or potassium fluoride, since they may be replaced by other substances, such as piperasine, acetalnid, ammonium tbiocyanate or sodium silicates. When solutions are prepared with these materials, it is advisable to incorporate a small amount of preservative, such as chlorphenol, to render the solution resistant to attack by micro-organisms. I have also found that the quantities of these peptlsing ordispe'rsing agents required may be greater than the quantity of sodium fluoride required to peptize the same amount of casein. Hence, for most purposes, sodium fluoride is more economical. For this reason, I prefer ordinarily to use sodium fluoride, since it combines both a dissolving and preserving action, but I wish to make it clearly understood that this invention is not limited to the use of fluorides only.

I have stated above that the solution prepared according to my process may be rendered alkaline. I have used a large variety of alkalis for this purpose satisfactorily and mention some of them here by way of example. I may take the casein solution which has been prepared in the manner disclosed herewith, for example, and add such amounts of any of the following, or mixtures thereof. as will bring this solution to the desired pH value: sodium silicates, diethylamine, ethylamlne, ammonium hydroxide. ethanolamine, diethanolamine, trlethanclamine. ethylene diamine. plperadine. plperaaine, borax. trisodium phosphate. sodium carbonate. ammonium carbonate, caustic soda.

1 A typical example of my process is the follow- To 100 parts of hydrochloric acid-precipitated casein are added 15 parts of commercial sodium fluoride and 200 parts of water and the whole stirred quickly to a thin uniform grainy mass. The casein quickly soaks up the liquid present and presents the appearance of a damp. granular meal, any lumps present being readily friable. After attaining this condition within a' few minutes. and after standing long enough for the casein granules to become thoroughly soaked, the

ably to 195 l t, at approximately this temperature for from a few minutes to several hours, until it forms a smooth stiif pasty solution. The time of treatment chosen depends upon using ordinary commercial acid-precipitated casein, I prefer to heat the mixture at this stage for from 56 hour to 1 hour. During the heating. the casein appears to melt into the viscous condition referred to and loses all of its grainy characteristics. The resulting solution may be diluted. preierably while still warm. As an example of such dilution, 250 parts of water are added at 120 F. after the mass has been suiliciently heated and changed from a coarsely granular mass to a smooth still pasty one. The resulting solution will be at about 180 F. to 170' I"., at which temperature the dilution under continuous stirring may be completed. This latter temperature at which the dilution is carried out is not impor tant. but I prefer not to let the mass become too cold, since it is difilcult to thin the viscous mass at low temperat Too high temperatures must be avoided, for example 200' It, for considerable lengths of time, since they may cause darkening of the product. The pH value of the resulting solution will be about 8.1, and if desired the solution may be partly neutralized or rendered slightly alkaline by the addition of suitable alkalis, such as borax, ammonium carbonate, etc. It is to be noted that the solution and stabilization of the casein is brought about during the initial heating stage and not by subsequent dilution. This dilution is performed to vary the consistency of the solution for the aforementioned purposes.

Following the preparation of the solution as outlined above, it is allowed to cool to normal temperatures, or, if desired. it may be cooled more rapidly with any convenient and suitable cooling medium.

It is to be noted that a solution may be rendered alkaline before the addition of the thinning water. or, if desired, the alkali may be added simultaneously with the thinning water. or. if desired, after the solution has been fully thinned down to the desired consistency. The order of addition of alkali and water following the initial heating and stabilizing treatment is not important.

Although I am well aware that the casein in my compositions may not be truly dissolved, the term "solution" in the appended claims is employed to cover. generally a casein composition which: (a) appears homogeneous to the naked eye; (b) can be diluted under stirring to a flowing viscous gluelike liquid of adhesive characteristics; (c) does not coagulate to a curdy mass which characterized by and 10.5, consisting characterised by its smoothtothenahed on 8118! withalli tula: a d

eye when smeared relatively rich, in casein.

is) when a solution, has thezcharaoteristics iiow slowly. 1 I s ng the characteristic oi stability over long periods oi time, my solutions can be shipped or kept until. in the. usual course oi busines they are utilized. although the initial viscosity oi a solution is ordinarily determined within a low days aiter its preparation, subsequent measurements made up until the time oi their use have indicated the cosity oi my solutions to be substantially unii rm or substantially undiminished. This invention is not to berestrictedto temperatures, percentages, or other exemplary data given, except as governed by the appended claims.

I clail'nt. I

1. A'caseln solution characterised by its stability and uniform viscosity over long periods oi time, having a pH value irom 8.0 to. 9.0.

2. A casein solution comprising the heat-reaction product 0! casein, sodium fluoride and water.

undiminished viscosity over long periodsoi time and having a pH value 017.0 to 10.5.-

9. The process oi producing a casein solution characterized by its stability and'substantial y -.undiminished viscosity over long periods oi time and having pH values within the limits oi 5.!

heating casein in the priesinsuiilcient oi itseli to and an alkali metal fluoride at temperatures ranging irom 170-310 1''.

4. The process 0! producing a casein solution stability and substantially undiminlshed viscosity over long periods oi time and having pH values within the limits oi 5.7 oi heating casein in the presence oi water and an alkali fluoride at temperatures ranging irom 170-210 I".

5. The process oi producing a casein solution characterized by its stability and substantially undiminished viscosity over long periods 01' time and having pH values .wlthin h and 10.5, comprising heating casein in the presence oi water and an alkali fluoride at temperatures ranging irom 190-195 1".

0. The process oi producing a casein solution characterized by its stability and substantially undiminished viscosity over long periods oi time and having pH values within the limits oi 5.7 and 10.5, comprising heating casein in the presence oi water and sodium fluoride at temperatures ranging irom 170-210 I". andsubsequently diluting the reaction product with water.

'L'The process oi producing a casein solution characterized by its undiminished viscosity over long periods oi time and having pH values within the limits oi 5.7 and 10.5, comprising heating parts oi acidprecipitated casein, about -350 parts oi water and about 14-20 parts oi sodium fluoride at temperatures ranging irom rill-210 it, and subsequently diluting the reaction product with water.

8. The process oi producing a casein solution characterized by its stabiiity'and substantially undiminished viscosity over long periods oi time and having pH values within the limits oi 5.! and 10.5, comprising heating 100 parts oi acid-precipitated casein, about 125-850 parts isstiiigslwhichw its stability and substantiallylimltl 0! 5.7

stability and substantially 0! water and. about 14-20 parts oi analkali iliggrige at temperatures ranging irom 180- o. a casein solution More sh -its stability and "substantially no ed viscosity over long periods oi time having a pH value in the range oi 1.0 to 10.5.

10'. A casein solution characterized by its stability and substantially undiminished viscosity over long periods oi time which remains stable ior pH values in the range oi 5.1 to 10.5.

11. The process oi. producing a casein solution characterised by its stability d substantially undiminished viscosity over lon periods oi time andhaving pH values within the limits oi 5.7 and .105 comprising heating casein in the presence oi water and a casein solvent sttemperatures ranging irom -210 R, ior a time suiilcient to substantially completely dissolve the casein and until the resulting solution having a pH value within said limits has become stable.-

12. The process oi producing a casein solution characterised by its stability and substantially undiininished viscosity over long periods I oi time and having pH values within the limits 0! 5.7 and 10.5,comprising heating casein in the presence oi water and a casein solvent at temperatures'ranging irom -195 I". tor a time suilicient to substantially completelyidlssolve the casein and until the resulting solution having a 1 pH value within said limits has become stable.

18. The process oi producing a casein solu tion characterised b its stability and substantislly uniiorm viscosi over long periods-airtime and having pH values within the limits of 5.7 and 9.0, comprising heating casein in the presence of water, and an alkali fluoride at temperatures ranging irom 170-210 1".

14. The'proeess oi producing a casein solution characterized by its stability and substantially undlminished viscosity over long periods oi time and having pH values within the limits oi 1.0 and 10.5, comprising heating casein in the presence of water and a casein solvent at temperatures ranging irom 170-210 F. ior a time suiflcient to substantially completely dissolve the casein and until the resulting solution has become stable, and subsequently rendering the resuiting product alkaline in reaction.

. 15. The process oi producing a casein solution characterized by its stability and substantially undiminished viscosity over long periods oi time and having pH values within the limitsoi 7.0

and 10.5 comprising heating casein in the presence 0! water and an alkali fluorideat temperatures ranging iro in- 170-210 H, and: subsequently diluting the reaction product with water and rendering the same alkaline in reaction.

16. The process oi producing a casein solution characterized by its stability and substantially undiminished viscosity over long periods 0! time and having pH values within the limits oi 5.! and 10.5, comprising partly neutralizing excessive acid'compounds present in the casein, and heating the thus treated casein in the presence of water and an alkali metal fluoride, at temperatures ranging irom 1'70-210 1".

1'1. The process oi producing a casein solution characterized by its stability and uniiorm viscosity over long periods of time and having pH values within the limits oi 5.0 and 9.0 comprising heating casein in the presence oi water and a casein solvent at temperatures ranging irom 170-210 l"., ior a time sumcient to substantially completely dissolve the casein and until the resulting solution has become stable and rendering the product alkaline.

18. The process of producing a casein solution characterized by its stability and substantially undiminished viscosity over long periods of time and having pH values within the limits of 5.7 and 10.5 comprising heating casein in the presence ct water and sodium fluoride at temperatures ranging from 180-195 I".

19. A casein solution comprising the heat (180495 F.) reaction product of casein, a solvent therefor and water, characterized by its stability and substantially undiminished viscos- Patent No. 235L100.

CARL IDDINGS vent therefor and water. characterized by its 5 stability and substantially undiminshed viscosity over long periods of time which remains stable for pH values in the range of 5.7 to 10.5.

bility and substantially uniform viscosity over long periods of time. havin: a pH value from CARL IJJDIN'GB- CERTIFICATE or commoner.

April 11, 19 9.

21. A casein solution characterized by its sta- It is hereby certified that error appears in the printed specification oi the above numbered patent requiring correction as follows: Page 1, first, column, line 15, for "displayes a" read displays no 3 same iine,be.fore 'is"' insert and; andthat the said Letters Patent should beread this correction therein that the same may conform to the record of the ease in the Patent Office Signed and sealed this 16th day of liq, A. Del-939.

Henry Van Airedale 'aetirg comissioner of Patents.

completely dissolve the casein and until the resulting solution has become stable and rendering the product alkaline.

18. The process of producing a casein solution characterized by its stability and substantially undiminished viscosity over long periods of time and having pH values within the limits of 5.7 and 10.5 comprising heating casein in the presence ct water and sodium fluoride at temperatures ranging from 180-195 I".

19. A casein solution comprising the heat (180495 F.) reaction product of casein, a solvent therefor and water, characterized by its stability and substantially undiminished viscos- Patent No. 235L100.

CARL IDDINGS vent therefor and water. characterized by its 5 stability and substantially undiminshed viscosity over long periods of time which remains stable for pH values in the range of 5.7 to 10.5.

bility and substantially uniform viscosity over long periods of time. havin: a pH value from CARL IJJDIN'GB- CERTIFICATE or commoner.

April 11, 19 9.

21. A casein solution characterized by its sta- It is hereby certified that error appears in the printed specification oi the above numbered patent requiring correction as follows: Page 1, first, column, line 15, for "displayes a" read displays no 3 same iine,be.fore 'is"' insert and; andthat the said Letters Patent should beread this correction therein that the same may conform to the record of the ease in the Patent Office Signed and sealed this 16th day of liq, A. Del-939.

Henry Van Airedale 'aetirg comissioner of Patents. 

